CVE-2026-54130
Critical
Description
Missing authentication for critical function in M365 Copilot allows an unauthorized attacker to disclose information over a network.
SeverityCritical
CVSS9.8
Exploit probability—
Product
Microsoft 365 Copilot
PublishedJun 18, 2026
First seenJun 18, 2026
Weakness typeCWE-306Missing authentication for critical function
How to fix
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| microsoft 365_copilot | No range specified | — |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
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